Metal encased refractory brick and method of making



R. M. FOCHT Nov. 29, 1966 METAL ENCASED REFRACTORY BRICK AND METHOD OF MAKING Filed May 12, 1964 5 Sheets-Sheet 1 INVENTOR ROBERT M. FOCHT ATTORNEYj R. M. FOCHT Nov. 29, 1966 METAL ENCASED REFRACTORY BRICK AND METHOD OF MAKING Filed May 12, 1964 5 Sheets-Sheet 2 INVENTOR BY\%74BMAIAI/M%Q ML ATTORNEYS Nov. 29, 1966 R. M. FOCHT 3,287,872

METAL ENCASED REFRACTORY BRICK AND METHOD OF MAKING 5 Sheets-Sheet 5 Filed May 12, 1964 INVENTOR ROBERT M. FocHT ATTORNEYS United States Patent Ofifiee 3,287,872 Patented Nov. 29, 1966 METAL ENCASED REFRACTORY BRICK AND METHOD OF MAKING Robert M. Focht, Lansdale, Pa., assignor to E. J. Lavino and Company, Philadelphia, Pa., a corporation of Delaware Filed May 12, 1964, Ser. No. 366,724 4 Claims. (Cl. 52-598) This invention relates to the manufacture of refractory brick and is directed particularly to the manufacture of metal jacketed brick.

In the construction of metallurgical furnaces, as well as furnaces for other uses, use is made of refractory bricks which are encased either wholly or in part in a sheet metal jacket. Such metal encased brick packages are of various shapes and sizes and can be used for both burned and unburned brick.

The sheet metal employed for covering the faces of the refractory brick body or for encasing the brick is of relatively heavy gauge steel and this rnust be cut to the proper dimensions to cover or substantially cover the face or surface of the refractory brick body to which it is to be secured. Consequently, since the bricks are produced in a variety of sizes and may be square or rectangular in form or tapered to different degrees, it is obvious that the cladding plates of sheet metal must also be cut in different sizes and shapes for use.

The metal cladding of refractory brick according to the present practice also requires the use of mastic for maintaining the applied cladding in position.

The present invention has for a particular object to provide a new metal encased refractory brick package wherein the encasing metal is-mechanically held on and about the refractory material.

Another object of the invention is to provide a new metal encased brick package and method of making the same in which a lighter gauge steel may be employed in such a 'manner as to obtain in the finished jacketed brick a plating thickness over the major part of the brick surface, of a thickness equivalent to the previously employed heavier gauge steel plate material.

Still another object of the invention is to provide a method of jacketing refractory brick material by the use of angular metal units or sections applied to burned or unburned brick of square or rectangular cross section or of tapered form, in such a manner as to completely encase the brick and provide the metal sheathing or coverage required.

More specifically the invention has for its object to provide a metal encased brick package employing for each refractory, four lengths of angle shaped metal assembled on and around the refractory body in such a manner as to have the angle flanges in overlapping relation whereby such overlapping angle flanges of the four pieces of metal material provide a cladding of substantial thickness and the overlapping angle flanges are joined one to the other by weld spots located at selected points near the longitudinal edges of the flanges. Thus, the overlapping flanges of the four coacting parts of angle material adjust to bricks of different Widths and thicknesses and will also adjust, within prescribed limits, to bricks of tapering form.

A still further object of the invention is to provide a novel method of cladding refractory brick bodies with steel jacketing material, by the use of four lengths of angle shaped steel, assembled as hereinabove described and have embossments to provide for thermal expansion and space between overlapped angles or flanges for oxidation of the steel.

A further general object of the invention is to provide an improved steel jacketed refractory brick structure employing four jacketing angles which are readily adaptable to a great variety of brick, both in size and tolerance to produce a superior, tighter fitted, metal encased brick.

Other objects and advantages of the invention will become apparent as the description of the same proceeds and the invention will be better understood from a consideration of the following detailed description taken in connection with the accompanying drawings wherein:

FIGURE 1 is a view in perspective of a mechanically held metal encased four angle brick package constructed in accordance with an embodiment of the present inventf-ion and wherein the package is of straight rectangular orrn.

FIGURE 2 is a partially exploded perspective view of the structure of FIGURE 1 showing two of the metal jacketing angles withdrawn from the partially assembled structure.

FIGURE 3 is a cross sectional view taken substantially on the line 33 of FIGURE 1 and on an enlarged scale.

FIGURE 4 illustrates a cladded brick of tapered form in which the cladding is provided by four straight jacketing angles such as those shown in FIGURE 1, the angles being applied to a brick of rectangular cross section.

FIGURE 5 illustrates a brick of square cross section, but tapered, and showing the application of straight jacketing angles thereto.

FIGURE 6 is a transverse section taken on the line 6-6 of FIGURE 5.

FIGURE 7 illustrates a straight brick structure of square cross section showing a modified form of the jacketing angles with certain of the flanges dimpled and two overlapped flanges punched into a formed recess in the refractory material of the brick.

FIGURE 8 is a cross sectional view taken substantially on the line 88 of FIGURE 7.

FIGURE 9 illustrates a tapered brick of square cross section having the flanges of one angle member dimpled.

FIGURE 10 is a perspective view corresponding to FIGURE 9 but showing the application of the angles to a tapered brick of rectangular cross section.

FIGURE 11 is an exploded perspective view showing the relative relationships of the four jacketing angles and a refractory brick body of square cross section and illustrating the dimpling of certain of the flanges of the angles and illustrating a button and dimple connecting means between an angle flange and a face of the refractory brick body.

FIGURE 12 is a perspective view of a completed brick package formed from the assembling of the parts shown in FIGURE 11.

FIGURE 13 is a cross sectional view taken substantially on the line 13-13 of FIGURE 12.

FIGURE 14 is a sectional detail illustrating an interlocking dimple connection between two overlapping flanges and a dimple in the side of the refractory brick body. 1

FIGURE 15 is a perspective view of an extremely tapered brick showing a modified formation of the jacketing angles.

Referring now more particularly to the drawings, the reference character B designates in FIGURES l to 3 a formed brick body of suitable or desirable refractory composition and such body may be either a burned or unburned brick body.

The body B is here illustrated as being of rectangular cross sectional form and straight throughout its length or, in other words, untapered.

The narrow face of the brick body is designated while the wide or broad face is designated 12.

As is clearly illustrated in FIGURE 1, which illustrates a complete brick package formed in accordance with the present invention, the wide and narrow faces which can be here seen, are completely covered or clad by overlapping legs of cladding angles such as are hereinafter described, and FIGURES 2 and 3 show that the wide and narrow faces not illustrated in FIGURE 1 are likewise covered with cladding metal.

The construction of a clad or completely jacketed refractory brick in accordance with the present invention is accomplished by the provision of four lengths of metal angle material which for the cladding of the majority of the refractory bodies of square or rectangular cross section and whether straight throughout or tapered, are assembled on the refractory brick material with the legs of the angles in overlapping relation and secured together so that the brick body is completely tightly jacketed or encased on all sides, the end faces only being uncovered.

Where the refractory body B may be tapered the same complete jacketing will be obtained by the overlapping legs of the angles but the overlap will be of a greater degree at the narrower end of the body than at the wider end on two opposite sides of the body.

In FIGURES l, 2 and 3 there are illustrated four lengths of metal angle material each of which is generally designated 14 and each of which may be generally referred to as an angle. These angles are applied to and encase a straight body of refractory material which is of rectangular cross section and each angle 14 accordingly has a wide leg 16 and a narrowleg 18.

The angles 14 are cut square across at their end edges and the free longitudinal edges of the wide and narrow legs 16 and 18 are parallel with one another and perpendicular to the end edges 20 and are respectively designated 22 and 24.

The length of each angle 14 may be the same as or slightly less than the length of the body B and the widths of the wide and narrow legs 16 and 18 may be slightly less than the wide and narrow faces of the brick body.

The brick body B is jacketed by placing each of two diagonal longitudinal edges in a metal angle 14 so that the wide legs 16 of the two angles are positioned against the opposite wide sides of the body B after which the other two metal angles 14 are put in position to enclose the other two diagonal corners of the brick body and thus, in the case of the jacketing of a brick body of rectangular cross section as shown in FIGURES 1 to 3, two

of the narrow legs 18 will come into overlapping relation r configuration may also be used for jacketing a brick body of rectangular cross section and of tapered form or a body of square cross section and tapered form as illustrated in FIGURES 4, 5 and 6.

In FIGURE 4 the body of refractory material is designated B-1 and is shown as being of rectangular cross section and as having the narrow side faces 28, one only of which is illustrated, tapering from the top to the bottom .end. In this case the opposite wide faces would be paralleL The metal angles 32 here shown would be placed with the narrow legs 34 in overlapping relation against the narrow faces 28 of the brick body while the wide legs 36 of the angles would also be placed in overlapping relation but, as illustrated, the overlap at the bottom end of the brick or the narrower end would be greater than the overlap at the opposite or top end. However, the metal cladding would be complete over each wide face of the brick body and the overlapping legs would be secured together by spot welding as at 38.

Where the taper of the body B1 is not excessive the tilting or cocking of the wide overlapping legs will not be sufficient to project the corners beyond the top and bottom surfaces of the brick. However, in the cladding of bricks where there is an extreme or sharp taper a modification of the legs of the angles is required as will be hereinafter described.

In FIGURES 5 and 6 the application of the straight angles to the four faces of a tapered brick body of square cross section is illustrated. In these figures the refractory brick body is generally designated B-2 and the metal angles, four in number, are each designated 40 and as shown in the cross sectional view forming FIGURE 6 the two legs 42 and 44 of these angles 40 may be of approximately the same width so that the extent of overlap is approximately the same and the outside legs of the two diagonally located angles 40 are welded as at 46 to the faces of the underlying legs of the other two angles.

As will be seen in FIGURE 5 the equal width legs 42 and 44 of the angles overlap at the wide portion of the body face 48 and also at narrower lower end of this face but overlap to a greater extent.

While the use of a mastic is not necessary to maintain the four angles in assembled relation on the brick body, it could be used if desired although the placing of the four angles together in the leg overlapped relation and the welding of the legs together will form a firm or tight connection with the body of refractory material.

FIGURES 7 and 8 illustrate a method of looking a pair of the angles together and to the refractory brick body and certain of the angles are illustrated with dimples or depressions formed in the legs which provides for thermal expansion and space for oxidation of the steel.

In FIGURES 7 and 8 the refractory brick body is generally designated B-3. These bodies are here illustrated as being of square cross section but they may be of rectangular form as shown in FIGURES 9 and 10 and while they are shown to be straight throughout they may also be tapered as shown in FIGURES 9 and 10.

The jacketing or cladding angles for the bodies B-3 encase the body with the legs of the angles in overlapping relation as hereinbefore described. Two of the angles encasing the bodies B-3 are designated 50 while the other two are designated 52.

The two legs 54 for each angle 50 are here shown as flat throughout.

One of the angles 52 :has the two legs 56 and 58 thereof dimpled to form the inwardly projecting buttons 60 which lie against adjacent faces of the brick body as illustrated. When the angles are assembled with the inwardly projecting portions or buttons 60 of the legs 56 and 58 disposed against the brick body, the leg '62 of the other angle 52 overlaps the leg 56. These overlapping legs 56 and 62 are welded together adjacent to, or a short distance inwardly of the longitudinal edges, as indicated at 64. They are then pierced or punched inwardly as indicated at 66 into a recess "68 molded into the surface of the refractory brick body. This provides a locking connection between the angles and the brick body.

FIGURES 9 and 10 illustrate the use of the four angles for cladding or encasing bricks of tapered form and of either a square cross section or rectangular cross section and in these figures the reference characters B-4 and 8-5 designate the refractory brick.

In the construction shown in FIGURE 9 the taper is on the wide sides 70 of the brick body. Accordingly, the

O angles 72 and 74 here shown will have the wide legs 76 of the same width as the wide side 70 of the brick while the narrow leg 78 will be slightly tapered as shown, whereby the top edge 80 thereof will approximate the width of the narrow side 82 of the brick body while the bottom edge 84 will approximate the width of the narrow side 82 of the brick at the lower or tapered end of the brick body.

The numeral 86 designates dimpling in the legs of the angles lying against the faces of the refractory brick body and as shown the outer longitudinal legs of the angles may be welded as at 88 to those legs of the inner angles.

FIGURE shows a tapered refractory brick which is generally designated BS having the wide and narrow sides or faces 90 and 92 covered by overlapped wide and narrow legs of straight angles designated 94 and 96, the wide and narrow legs of which angles are mspectively designated 98 and 100.

This FIGURE 10 illustrates how the wide legs of the angles overlap to cover substantially the entire area of the wide faces 90 of a tapered brick of rectangular cross section. The angles 94 and 96 have the wide and narrow legs thereof of the same width from end to end as in all the previously described forms, with the exception of the angles shown in FIGURE 9, and the overlapping legs are secured together by welding at selected points near the longitudinal edges of the outside legs as indicated at 1122. Also, the legs of the inside angles may be provided with dimpled areas as indicated at 104.

In referring to the inside angles as being dimpled, it is to be understood that the dimpling may take any shape or form and also while the drawings re resent the di-mpling as extending substantially over the entire areas of the legs, the dimples or impresed portions of the legs may be located only at a few points as, for example, there may be some dimples, ridges or other deformations located only at the top and bottom portions of the legs or along and adjacent to the free edges thereof, as may be desired or found most feasible in connection with the manufacturing of the angles.

FIGURES l1, l2 and 13 illustrate another construction or another metal encased brick package in which certain of the legs of the inside angles are dimpled at selected locations and in which a coupling is effected between a leg of an inner angle and a face of the body of refractory material by means of a dimple engaging in a depression in the face of the brick.

FIGURE 11 is an exploded perspective view of a construction in which the brick body, generally designated B6, is of square cross section and straight throughout and .wherein the completed package will be of the same configuration as illustrated in FIGURE 12. It is to be understood, however, that the assembly here illustrated could embody a brick of rectangular cross section and also one of tapered form, that is, either tapered on two opposite wide sides or faces or tapered on two opposite narrow faces.

In the form of the invention under consideration one of the longitudinal side faces, here designated 165, is provided with a depression or recess 1% at some selected location along its length and preferably midway between the longitudinal edges 168 of the recessed face.

The angles which when assembled form the jacket or casing for the brick body are designated 11 112, 114 and 11-6.

Being designed to encase a body of square cross section it will be apparent that the legs of the four angles may, if desired, all be of the same width although this is not essential.

The angles 110 and 112 are illustrated in the position where they will enclose or receive diagonally separated corners of the brick body and will therefore constitute the inner angles or covered angles since the other two angles designated 114 and 116 receive the other diagonally separated corners of the brick body and wil also have their legs in covering relation with the major portions of the legs of the inner angles and 112. This arrangement is clearly shown in FIGURES 12 and 13 where the angles 110 and 112 are shown on the inner sides of the angles 114 and 116.

The leg 118 of angle 112 is dimpled or pressed to form an inwardly projecting button 120 at the properly located position where when the angle 112 is applied to the body B6, the button formed by the dimple will enter the depression or recess 106 in the face 104 of the brick body, as illustrated in FIGURE 13.

As stated, certain of the legs of the inner angles may be provided with dimples forming inwardly projecting buttons or raised portions formed in any other suitable manner to contact the opposing surface of the brick body and such button forming dimples are here shown as being pressed or molded in the leg 122 of angle 112 and leg 124 of angle 110 and the dimples or impressed portions of the metal are designated 126 and show upon the inner side of the angle leg 124 as the inward projections 128.

The legs of the outside or covering angles 114 and 116 are welded at selected points to the underlying legs of the inner angles as indicated at 130.

In addition to welding together overlapping legs of the four angles whereby the refractory brick body becomes completely tightly encased in metal covering or sheathing on all sides, two overlapping legs may be pressed or punched in, into a recess or depression molded into the surface of the refractory brick over which such legs lie. For example, FIGURE 14 illustrates a portion of a refractory brick body which is generally designated B7. The numerals 132 and 134 designate respectively portions of legs of two angles, the portion 132. being the inner portion or inner leg of one angle and the portion 134 being the outer portion or outer leg of a covering angle while the numeral 136 designates a depression formed in the surface of the refractory brick body and corresponds to the depression or recess 166 as shown in FIGURE 11.

The positions of the punch points and the recess 136 are, of course, calculated to come into the proper relationship when the angles are applied to the body so that when the metal of the leg portions 132 and 134 is pressed or punched inwardly there will be formed the interengaged button-like projections 138 and 140 lying one within the other with the inner projections 138 extending into the recess 136, thus there will be provided an additional attaching means between the angles and the body of the brick.

As will be evident from the preceding description of the invention, a complete jacketing or sheathing of the refractory brick bodies of square or rectangular cross section and either of straight form or tapered form, can be effected by the use of four elongate members of angular cross section assembled on or across the corners of the brick body so as to have two opposite angles directly against the brick body and the other two angles with their legs overlapping the legs of the first two angles. Thus, the over-lapping legs of the four angles will provide complete coverage for the four side faces of the brick body. For a brick body of relatively small cross sectional contour the overlapping legs of the angles would provide a double thickness sheathing over each of the side faces of the brick body and where the brick body may be of larger cross sectional dimension angles of the same size might also be used but the overlap of the legs would not be as great as in the case of the smaller brick. Also, it would be apparent that in the majority of cases the angles might be formed from material in which the legs are the same width throughout, but in exceptional cases where the taper of the brick may be extreme or on narrow sides of the brick as in FIGURE 9 so that corners of the legs of the applied angles might project beyond an end face of the brick, then one leg of each angle might be tapered or disposed at an angle along its free edge to the opposite side or corner of the angle. I

FIGURE illustrates a condition of extreme modification of the legs of the four angles for covering the sides of an extremely tapered brick body. In this figure the brick body or the body of refractory material molded to the desired form is generally designated B8. As shown, this body is of rectangular cross section and the numeral 142 designates the opposite wide faces while the opposite narrow faces are designated 144. The narrow faces 144 are shown as converging sharply from the top to the bottom or lower end of the body and consequently the side faces 142 decrease rapidly in width but may be parallel to one another.

Three of the four sheathing angles are shown in this FIGURE 15. The outer angles are designated 146 while the single inner angle shown is generally designated 148, it being understood, of course, that there is a corresponding one on the opposite side of the body. The narrow leg of the angle 146 is designated 150 while the corresponding narrow leg of the inner angle 148 is designated 152. These narrow legs of the sheathing angles extend over the narrow side of the body, in overlapping relation one with the other, and may be of the same width throughout their length as the narrow side of the brick body.

The other and wide legs of the angles 1-46 and the angles 148 are designated respectively 154 and 156. The free longitudinal edges of these legs 154- and 15-6 are convergent with the corners of their respective angles. Thus, when the four sheathing angles are assembled the wide legs of the angles will overlap and substantially completely cover the adjacent wide side or face of the brick body.

The overlapping plates may then be secured together by welding as at 158. Also, if found desirable or necessary, suitable mastic may be used to bond the angles in overlapping relation against the faces of the refractory brick material.

While reference has been made to the use of four angle members for sheathing or covering four faces of a refractory brick body, it will also be apparent that the objectives of the invention may be accomplished by the employment of two angle members, .for example, so that the desired cladding may be obtained upon one face of the brick of refractory material and at least over the major extent of each of two faces contiguous to the fully cla-d face. Thus, if reference is had to FIGURE 3, for example, it will be seen that one wide face of the body of refractory material is covered by two overlapping legs of two angle members which together completely cover or clad the Wide face of the brick body. These two overlapping wide legs of the angle members aredesignated 16 and it will be seen that the narrower legs of the same two angle members will each extend over a substantial area of a narrow side or face 10 of the brick body. This arrangement provides a novel means of cladding one wide face or one face only of the brick body and partially cladding or covering two opposite faces, leaving the fourth face, which may be a wide face as in the structure shown in FIGURE 3, unclad.

Angles of the same size may be used upon the brick bodies of different Widths and thicknesses within wide limitations and by the overlapping of the legs of the angles, angles may be formed of sheet metal of materially lighter gauge than is at present employed and at the same time the total thickness of metal protecting the face of the brick body could be the same or substantially the same as the previously used thick metal plate.

In using two angles in the manner above described, the same welding technique might be employed, the welding being done near the free longitudinal edge of the outermost one of the two overlapped legs and in addition this arrangement might be employed in combination with mastic for holding the two angles bonded to the faces of the brick body or a punching operation might be em ployed such as is illustrated in FIGURE 8 with the weld- 8 ing operation alone or in combination with the welding and the use of mastic.

While the projecting parts of the legs of certain of the angles have been shown lying against the sides of the refractory brick body and such projecting portions have been illustrated and described in connection with the legs of the inner angles, legs of the outside angles may also be provided with such portions to effect a slight separation between the overlapping inner and outer legs to allow for thermal expansion and space for oxidation of the steel of the angles.

It will be readily apparent from the foregoing description and illustration of the invention that another advantageous feature of the present invention resides in the fact that the angles which encase the four corners of the brick body may be formed of a lighter gauge steel than that at present used for plating or cladding refractory bricks. The use of the lighter gauge steel and the disposition of the legs of the angles in overlapping relation with one another provides a cladding or plating of the brick surface having a thickness substantially equal to the thickness of the heavier gauge steel presently used and applied as separate or single fiat plates against the individual faces of the brick body.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents, are therefore intended to be embraced by those claims.

I claim:

1. A refractory brick package, comprising a brick body of refractory material having a quadrangular cross section and intersecting side faces forming longitudinal corners, two elongate metal bodies of single angle cross section each having two legs each of a width materially greater than one-half the width of the said side faces of the brick body, two diagonally spaced corners of the brick body being positioned in the angles of said two metal bodies whereby each leg of each metal body lies against and extend widthwise across more than half the width of the two adjacent intersecting side faces, two other elongate metal bodies of single angle cross section each having two legs, two other diagonally spaced corners of the brick body being positioned in the angles of the said two other metal bodies, the legs of the said other metal bodies extending widthwise across at least half the width of the two adjacent intersecting side faces of the brick so as to overlap and lie against the outer sides of adjacent legs of the first two metal bodies, and means joining the legs of the said two other metal bodies to the adjacent legs of the first mentioned metal bodies, the said overlapping legs of the several metal bodies providing substantially complete metal cladding of the brick body.

2. A refractory brick package according to claim 7, wherein dimples are provided in the overlapped legs by forming portions of the metal of the legs offset from the planes of the legs.

3. A refractory brick package according to claim 1, wherein the body of refractory material is provided in at least one face thereof with a recess into which extends a portion of the metal of a metal body leg lying thereagainst.

4. The method of manufacturing a metal clad refractory brick which comprises the steps of forming a brick body of refractory material in a desired length and of rectangular cross section and having side surfaces intersecting to form longitudinal corners, then placing a separate length of metal angle material over each of the two opposed diagonal longitudinal corners of the brick body, then placing a separate length of metal angle material over each of the remaining opposed diagonal corners with each leg of each of the metal angles extending at least halfway across the respective side surface of the brick so "as to overlap the legs of adjacent angles and in a relationship wherein two legs of certain angles will lie upon the outside of legs of other angles and have exposed longitudinal edges, and then securing all of the angles together to form metal cladding over each of said surfaces of the brick body.

References Cited by the Examiner UNITED STATES PATENTS Re. 25,615 Re. 25,755

10 2/ 1956 Coffman et a1 52-599 8/1958 Mason et a1. 110--99 12/1959 Wilkins 52-309 1/ 1963 Shonkwiler 52-599 X.

FOREIGN PATENTS 5/ 1955 Austria.

10 FRANK L. ABBOTT, Primary Examiner.

A. C. PERHAM, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,287,872 November 29, 1966 Robert M. Focht It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 8, line 58, for claim reference numeral "7" read l 0 Signed and sealed this 12th day of September 1967.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

1. A REFRACTORY BRICK PACKAGE, COMPRISING A BRICK BODY OF REFRACTORY MATERIAL HAVING A QUADRANGULAR CROSS SECTION AND INTERSECTING SIDE FACES FORMING LONGITUDINAL CORNERS, TWO ELONGATE METAL BODIES OF SINGLE ANGLE CROSS SECTION EACH HAVING TWO LEGS EACH OF A WIDTH MATERIALLY GREATER THAN ONE-HALF THE WIDTH OF THE SAID SIDE FACES OF THE BRICK BODY, TWO DIAGONALLY SPACED CORNERS OF THE BRICK BODY BEING POSITIONED IN THE ANGLES OF SAID TWO METAL BODIES WHEREBY EACH LEG OF EACH METAL BODY LIES AGAINST AND EXTEND WIDTHWISE ACROSS MORE THAN HALF THE WIDTH OF THE TWO ADJACENT INTERSECTING SIDE FACES, TWO OTHER ELONGATE METAL BODIES OF SINGLE ANGLE CROSS SECTION EACH HAVING TWO LEGS, TWO OTHER DIAGONALLY SPACED CORNERS OF THE BRICK BODY BEING POSITIONED IN THE ANGLES OF THE SAID TWO OTHER METAL BODIES, THE LEGS OF THE SAID OTHER METAL BODIES EXTENDING WIDTHWISE ACROSS AT LEAST HALF THE WIDTH OF THE TWO ADJACENT INTERSECTING SIDE FACES OF THE BRICK SO AS TO OVERLAP AND LIE AGAINST THE OUTER SIDES OF ADJACENT LEGS OF THE FIRST TWO METAL BODIES, AND MEANS JOINING THE LEGS OF THE SAID TWO OTHER METAL BODIES TO THE ADJACENT LEGS OF THE FIRST MENTIONED METAL BODIES, THE SAID OVERLAPPING LEGS OF THE SEVERAL METAL BODIES PROVIDING SUBSTANTIALLY COMPLETE METAL CLADDING OF THE BRICK BODY. 